1. Field of the Invention
The present invention relates to a technique for displaying an image in the process of being exposed.
2. Description of the Related Art
When a subject having a low luminance, such as a night view, a celestial body, etc., is photographed, long exposure shots having a long exposure time are taken. In such a long exposure shot, it takes a long time to obtain a shot image, and thus it takes much time to check whether a desired image has been obtained or not.
In order to address this problem, there is a technique in which an exposure in a long exposure shot is divided into a plurality of times of exposures, and a user is allowed to check a shot image in the process of being exposed on a display section each time individual exposure is terminated (for example, Japanese Unexamined Patent Application Publication No. 2004-140484). By this technique, a determination can be made on whether a desired image is obtained during the exposure, and thus it becomes possible to determine whether a captured image is good or bad in a short time.
However, in a long exposure shot, a subject has a low luminance, and thus the signal level of a displayed image is low at the beginning of the exposure, thereby making it difficult for the user to check a picture composition.
As a technique allowing the user to check a picture composition in an early stage, for example, there is a technique in which an image signal of an image in the process of being exposed is amplified, and the amplified image signal is displayed (for example, Japanese Unexamined Patent Application Publication No. 2003-69897). By this technique, even in the case of shooting a subject having a low luminance, it is possible to check a picture composition of a captured image in an early stage after the start of an exposure, and thus it becomes possible to discover a shot with an inadequate composition, or an inadvertent appearance of an unnecessary object in a picture at the early stage.